The other thing I can't figure out is why every single time I start BIAB on my Laptop I get a pop-up error box as seen in the attachments below.
How is the Casio connected? What kind of USB interface do you have?
The Casio goes directly from a USB out from the keyboard into the USB of the computer. No driver is needed as it is recognized by the computer and shows up in BIAB as a MIDI input device just fine. Presumably you do not get that error if you have the MIDI interface disconnected when you start Band-in-a-Box?